Simple rotary broach - video

[Jon]

Simple rotary broach. By billzweig. 9:53 video:

[paul1950]

Simple rotary broach. By billzweig. 9:53 video:

Interesting video, lots of good toys BUT way too long and boring

[old kodger]

Judging by the amount. and type of equipment used, I wouldn't have a snowflake in hell's chance of making that.

[Frank S]

Judging by the amount. and type of equipment used, I wouldn't have a snowflake in hell's chance of making that.

No real reason why you couldn't bore the housing on your lathe, first drill a small pilot bore through the center, then with a 4 jaw center the part with 2 jaws then wrap a wire the diameter of the desired offset angle on the other 2 one wire to the inside near the chuck body and the other wire on the opposite jaw near the outside insert a long cylinder in the pilot bore to use as a means of checking for the correct angle using which ever measuring device you choose against the cylinder and the tool post, assuming you had previously set your tool post to zero angle. Remove the test pin drill and finish boring the housing to the desired ID you can even add a snap ring grove to secure the bearings. Since there is only 1 part to the assembly which is critical to the angularity of the broach's operation the rest of the tool should be straight forward machining or grinding. No fancy equipment required.
I did leave out one crucial step when setting the angle in the opposing jaws the end of the gage pin should come to center of where the tip of the broach ing tool will end up so 1 jaw will be set closer to center than the other this will help a lot to do this step, I would probably use a transfer punch as the gage pin for setting the angle so as to have a center point to check my offset

[old_toolmaker]

Interesting project and nice workmanship. Well done!

[wizard69]

pretty nice!

I only have one thing I don't understand, would it have not been more sensible to find the center before rotating the hub up. In other words bore the hub and then shim up the sine vice to get your bore angle? I ask because I could see a real benefit to having one of these in my shop so need to understand what is going on here. So wouldn't rotating up and then moving your Y axis be the same thing or at least suffer from fewer measurement errors. You would need ot move the Y axis less if I'm thinking right here.

df